Conventionally, a step unit is provided on a vehicle main body at a position that is adjacent to a vehicle sliding door. One type of typical step unit includes a step member and a drive device (motor unit), which is fixed to the step member and operates to open and close a vehicle sliding door. For example, refer to Patent Document 1.
In such a step unit, the step member is typically formed through sheet-metal processing and has a flat plate portion, on which occupants put their feet. The drive device is mounted at a position of the flat plate portion where the drive device is least obstructive to occupants. For example, the drive device is mounted at a position on the flat plate portion that is at the rearmost end.